Presence of hypervirulence-associated determinants in Klebsiella pneumoniae from hospitalised patients in Germany.

BACKGROUND: Klebsiella (K.) pneumoniae is a ubiquitous Gram-negative bacterium and a common coloniser of animals and humans. Today, K. pneumoniae is one of the most persistent nosocomial pathogens worldwide and poses a severe threat/burden to public health by causing urinary tract infections, pneumonia and bloodstream infections. Infections mainly affect immunocompromised individuals and hospitalised patients. In recent years, a new type of K. pneumoniae has emerged associated with community-acquired infections such as pyogenic liver abscess in otherwise healthy individuals and is therefore termed hypervirulent K. pneumoniae (hvKp). The aim of this study was the characterisation of K. pneumoniae isolates with properties of hypervirulence from Germany. METHODS: A set of 62 potentially hypervirulent K. pneumoniae isolates from human patients was compiled. Inclusion criteria were the presence of at least one determinant that has been previously associated with hypervirulence: (I) clinical manifestation, (II) a positive string test as a marker for hypermucoviscosity, and (III) presence of virulence associated genes rmpA and/or rmpA2 and/or magA. Phenotypic characterisation of the isolates included antimicrobial resistance testing by broth microdilution. Whole genome sequencing (WGS) was performed using Illumina® MiSeq/NextSeq to investigate the genetic repertoire such as multi-locus sequence types (ST), capsule types (K), further virulence associated genes and resistance genes of the collected isolates. For selected isolates long-read sequencing was applied and plasmid sequences with resistance and virulence determinants were compared. RESULTS: WGS analyses confirmed presence of several signature genes for hvKp. Among them, the most prevalent were the siderophore loci iuc and ybt and the capsule regulator genes rmpA and rmpA2. The most dominant ST among the hvKp isolates were ST395 capsule type K2 and ST395 capsule type K5; both have been described previously and were confirmed by our data as multidrug-resistant (MDR) isolates. ST23 capsule type K1 was the second most abundant ST in this study; this ST has been described as commonly associated with hypervirulence. In general, resistance to beta-lactams caused by the production of extended-spectrum beta-lactamases (ESBL) and carbapenemases was observed frequently in our isolates, confirming the threatening rise of MDR-hvKp strains. CONCLUSIONS: Our study results show that K. pneumoniae strains that carry several determinants of hypervirulence are present for many years in Germany. The detection of carbapenemase genes and hypervirulence associated genes on the same plasmid is highly problematic and requires intensified screening and molecular surveillance. However, the non-uniform definition of hvKp complicates their detection. Testing for hypermucoviscosity alone is not specific enough to identify hvKp. Thus, we suggest that the classification of hvKp should be applied to isolates that not only fulfil phenotypical criteria (severe clinical manifestations, hypermucoviscosity) but also (I) the presence of at least two virulence loci e.g. iuc and ybt, and (II) the presence of rmpA and/or rmpA2.

Rectal colonization is predictive for surgical site infections with multidrug-resistant bacteria in abdominal surgery.

PURPOSE: Superficial surgical site infections (SSI) are a common complication after abdominal surgery. Additionally, multidrug-resistant organisms (MDRO) have shown an increasing spread in recent years with a growing importance for health care. As there is varying evidence on the importance of MDRO in different surgical fields and countries as causative agents of SSI, we report our findings of MDRO-caused SSI. METHODS: We assembled an institutional wound register spanning the years 2015-2018 including all patients with abdominal surgery and SSI only, including demographics, procedure-related data, microbiological data from screenings, and body fluid samples. The cohort was examined for the frequency of different MDRO in screenings, body fluids, and wound swabs and assessed for risk factors for MDRO-positive SSI. RESULTS: A total of 138 out of 494 patients in the register were positive for MDRO, and of those, 61 had an MDRO isolated from their wound, mainly multidrug-resistant Enterobacterales (58.1%) followed by vancomycin-resistant Enterococcus spp. (19.7%). As 73.2% of all MDRO-carrying patients had positive rectal swabs, rectal colonization could be identified as the main risk factor for an SSI caused by a MDRO with an odds ratio (OR) of 4.407 (95% CI 1.782-10.896, p = 0.001). Secondly, a postoperative ICU stay was also associated with an MDRO-positive SSI (OR 3.73; 95% CI 1.397-9.982; p = 0.009). CONCLUSION: The rectal colonization status with MDRO should be taken into account in abdominal surgery regarding SSI prevention strategies. Trial registration Retrospectively registered in the German register for clinical trials (DRKS) 19th December 2019, registration number DRKS00019058.

Recurrent bacteremia with a hypermucoviscous Escherichia coli isolated from a patient with perihilar cholangiocarcinoma: insights from a comprehensive genome-based analysis.

BACKGROUND: Escherichia coli (E. coli) is a common human pathogen, responsible for a broad spectrum of infections. Sites of infection can vary, but the hepato-biliary system is of particular concern due to the infection-associated formation of gallstones and the spread of pathogens from the bile ducts into the bloodstream. CASE PRESENTATION: The presented case is striking, as the detected isolate showed a positive string test. This hypermucoviscous phenotype is atypical for E. coli and a particular feature of hypervirulent Klebsiella pneumoniae (K. pneumoniae) variants. OBJECTIVES: To provide new insights into the genomic background of an E. coli strain with an unusual hypermucoviscous phenotype using hybrid short- and long-read sequencing approaches. RESULTS: Complete hybrid assemblies of the E. coli genome and plasmids were done and used for genome based typing. Isolate 537-20 was assigned to the multilocus sequence type ST88 and serotype O8:H4. The strain showed a close relationship to avian pathogenic strains. Analysis of the chromosome and plasmids revealed the presence of several virulence factors, such as the Conserved Virulence Plasmidic (CVP) region on plasmid 537-20_1, including several iron acquisition genes (sitABCD, iroABCDEN, iucABCD, hbd) and the iutA gene encoding the receptor of the siderophore aerobactin. The hypermucoviscous phenotype could be caused by encapsulation of putative K. pneumoniae origin. CONCLUSIONS: Hybrid sequencing enabled detailed genomic characterization of the hypermucoviscous E. coli strain, revealing virulence factors that have their putative origin in K. pneumoniae.

[Typhoid and paratyphoid fever]. / Typhus abdominalis und Paratyphus.

Typhoid fever and paratyphoid fever are systemic infectious diseases of global significance caused by Salmonella enterica subspecies enterica Serovar Typhi (short name: Salmonella Typhi) or Serovar Paratyphi (short name: Salmonella Paratyphi). The course of these fecal-orally transmitted diseases is mainly characterized by a high fever. Left untreated, the course of typhoid fever can be severe and lethal. The infection is almost always acquired outside of Europe (mainly in India) and is notifiable in Germany, Austria and Switzerland. Paratyphoid is an attenuated disease of typhoid fever caused by Salmonella Paratyphi. Available vaccines only protect against Salmonella Typhi. Antibiotic resistance reflects the situation in endemic countries and shows a worrying increase of multi-drug resistant isolates. Currently, third-generation cephalosporins such as ceftriaxone are recommended as first-line therapy; if sensitive to quinolones, fluoroquinolones such as ciprofloxacin may continue to be administered. Crucial preventive measures for travelers to endemic regions include consistent water and food hygiene as well as vaccination, whereby only protection rates of 50-70 % are achieved by currently available vaccines. In the light of increasing multi-drug resistance, a more effective conjugate vaccine against Salmonella Typhi with cross-reactivity against Salmonella Paratyphi is needed more than ever.

Frequency and clinical presentation of alveolar and cystic echinococcosis in a tertiary medical center in Germany 2004-2018: lessons from a low-prevalence area.

INTRODUCTION: The prevalence of alveolar echinococcosis (AE) and cystic echinococcosis (CE) in Germany is increasing. The number of cases in northern and eastern regions is low, so there is little experience with regard to diagnosis and therapy. OBJECTIVES: The objective of this paper was to evaluate the management of suspected and/or diagnosed echinococcosis at a university center in a low-prevalence region. METHODS: All the patients at the Leipzig University Hospital between 2004 and 2018 who had been serologically examined for echinococci were included in a retrospective cohort study. Clinical course, imaging, histology, therapeutic characteristics, relevant comorbidities and risk factors for AE and CE were evaluated. A time-staggered prevalence estimation, as well as sensitivity and specificity calculations for the serological tests, were performed. RESULTS: A total of 382 patients were enrolled, with 11 AE and 7 CE cases identified. The mean prevalence rate of AE in this cohort was 2.9 % and that of CE was 1.8 %. Among the patients, 56 % had known risk factors for AE and CE. The serological tests showed a sensitivity of 86 % and a specificity of 91 %. Two patients with false-negative serology were diagnosed by biopsy. All CE and 5 AE patients (45 %) were operated on. Six AE patients received long-term treatment with albendazole. CONCLUSIONS: AE and CE are rare diseases in the greater Leipzig region; however, case numbers are on the rise. Due to favorable factors such as the escalation of migration, a further increase is expected. Diagnosis and therapy are challenging and should be supported by specialists (experienced infectiologists, imaging experts and skilled hepatobiliary surgeons) who should be integrated in a German network.

Environmental pollution with antimicrobial agents from bulk drug manufacturing industries in Hyderabad, South India, is associated with dissemination of extended-spectrum beta-lactamase and carbapenemase-producing pathogens.

PURPOSE: High antibiotic and antifungal concentrations in wastewater from anti-infective drug production may exert selection pressure for multidrug-resistant (MDR) pathogens. We investigated the environmental presence of active pharmaceutical ingredients and their association with MDR Gram-negative bacteria in Hyderabad, South India, a major production area for the global bulk drug market. METHODS: From Nov 19 to 28, 2016, water samples were collected from the direct environment of bulk drug manufacturing facilities, the vicinity of two sewage treatment plants, the Musi River, and habitats in Hyderabad and nearby villages. Samples were analyzed for 25 anti-infective pharmaceuticals with liquid chromatography-tandem mass spectrometry and for MDR Gram-negative bacteria using chromogenic culture media. In addition, specimens were screened with PCR for bla VIM, bla KPC, bla NDM, bla IMP-1, and bla OXA-48 resistance genes. RESULTS: All environmental specimens from 28 different sampling sites were contaminated with antimicrobials. High concentrations of moxifloxacin, voriconazole, and fluconazole (up to 694.1, 2500, and 236,950 µg/L, respectively) as well as increased concentrations of eight other antibiotics were found in sewers in the Patancheru-Bollaram industrial area. Corresponding microbiological analyses revealed an extensive presence of extended-spectrum beta-lactamase and carbapenemase-producing Enterobacteriaceae and non-fermenters (carrying mainly bla OXA-48, bla NDM, and bla KPC) in more than 95% of the samples. CONCLUSIONS: Insufficient wastewater management by bulk drug manufacturing facilities leads to unprecedented contamination of water resources with antimicrobial pharmaceuticals, which seems to be associated with the selection and dissemination of carbapenemase-producing pathogens. The development and global spread of antimicrobial resistance present a major challenge for pharmaceutical producers and regulatory agencies.

Possible pulmonary Rhizopus oryzae infection in a previously healthy child after a near-drowning incident.

This article reports on a previously healthy 17-month-old boy who developed pulmonary mucormycosis after a near-drowning incident in a goose pond. The patient survived without neurological sequelae and recovered, under treatment with amphotericin B, from the rare and often invasive fungal infection with Rhizopus spp., usually occurring in immunodeficient patients.

VP-shunt dysfunction caused by malaria CNS infection.

INTRODUCTION: Malaria is a widespread mosquito-borne infectious disease with over 300 million cases and roughly 900 thousand deaths in 2013. Cerebral involvement of malaria causes 50 % of all infection-associated deaths, especially in children below the age of 5 years. Hydrocephalus is a medical condition with abnormal accumulation of cerebrospinal fluid in physiological cavities and ventricles. Standard treatment is the implantation of a cerebrospinal fluid shunt device. A common problem associated with shunt treatment especially in pediatric patients is infection and consecutive shunt dysfunction caused by bacteriae or high protein levels clogging the valve. In these cases, Staphylococcus aureus and Staphylococcus epidermidis are predominantly found in CSF cultures. CASE PRESENTATION: We present a case of a 2-year old boy from Saudi Arabia with a ventriculoperitoneal (VP)-shunt-dependent congenital hydrocephalus who suffered from cerebral malaria and developed consecutive shunt failure. CONCLUSION: To the best of our knowledge, shunt failure caused by malaria CNS infection with Plasmodium falciparum has not yet been reported in the literature and should be considered as a rare cause of VP-shunt failure in patients with atypical VP-shunt infections living in or traveling from endemic areas.

Clinical management, pathogen spectrum and outcomes in patients with pyogenic liver abscess in a German tertiary-care hospital.

Pyogenic liver abscesses (PLA) are life-threatening disorders and require immediate treatment, but structured evidence is sparse and treatment guidelines are not established. In a retrospective observational study of 221 adult PLA patients (mean age 63 years, 63% men) treated between 2013 and 2019 at the Leipzig University Medical Center, we characterized pathogen spectrum, clinical management and outcomes. Biliary malignancies (33%), cholelithiasis (23%) and ischemic biliary tract disease (16%) were most common causes of PLA. Comorbidities included malignancies (40%) and diabetes mellitus (35%). Abdominal ultrasound was the preferred initial imaging modality (58%). Enterobacterales (58%), enterococci (42%) and streptococci (18%) were identified as most frequent pathogens. 97% of patients were treated with antibiotics and 75% of patients underwent an invasive treatment procedure. The 30-day mortality was almost identical in patients with and without underlying malignancy (14.6% vs. 14.4%, p = 0.96), while the one-year outcome differed significantly (58.4% vs. 29.6%, p < 0.001). Positive blood cultures (OR 4.78, 95% CI 1.39 to 22.5, p = 0.023) and detection of Enterobacterales (OR 3.55, 95% CI 1.40 to 9.97, p = 0.010) were associated with increased 30-day-mortality. We conclude that ultrasound, extensive microbiologic diagnosis, adequate anti-infective therapy and early intervention are crucial for the management of PLA.

Extended-spectrum beta-lactamases found in Escherichia coli isolates obtained from blood cultures and corresponding stool specimen.

With extended-spectrum ß-lactamases (ESBLs) and CTX-M enzymes being on the rise, antimicrobial treatment of enterobacterial infections is becoming more and more challenging. Our study aimed at a molecular characterization of phenotypically ESBL-positive E. coli strains obtained from blood cultures of patients of the University Hospital of Leipzig (UKL), Germany. The presence of CMY-2, CTX-M-14 and CTX-M-15 was investigated using Streck ARM-D Kit (Streck, USA). Real-time amplifications were performed by QIAGEN Rotor-Gene Q MDx Thermocycler (QIAGEN, Thermo Fisher Scientific, USA). Antibiograms as well as epidemiological data were evaluated. Among 117 cases, 74.4% of the isolates showed a resistance to ciprofloxacin, piperacillin and ceftazidime or cefotaxime while being susceptible to imipenem/meropenem. The proportion of ciprofloxacin resistance was significantly higher than the proportion of ciprofloxacin susceptibility. At least one of the investigated genes was detected in 93.1% of the blood culture E. coli isolates: CTX-M-15 (66.7%), CTX-M-14 (25.6%) or the plasmid-mediated ampC gene CMY-2 (3.4%). 2.6% were tested positive for two resistance genes. 94 of the corresponding stool specimens tested positive for ESBL producing E. coli (94/112, 83.9%). 79 (79/94, 84%) E. coli strains found in the stool samples matched with the respective patient's blood culture isolate phenotypically (MALDI-TOF, antibiogram). The distribution of resistance genes was in accordance with recent studies in Germany as well as worldwide. This study provides indications of an endogenous focus of infection and emphasize the importance of screening programs for high-risk patients.

The Value of Perinatal Factors, Blood Biomarkers and Microbiological Colonization Screening in Predicting Neonatal Sepsis.

Background: Neonatal sepsis is one of the most important causes of elevated morbidity and mortality rates in neonatal intensive care units worldwide. While the clinical manifestations of neonatal sepsis tend to be nonspecific, its rapid development and life-threatening potential call for reliable markers for early detection. Methods: We conducted a retrospective single-center study including all neonates suspected of having developed neonatal sepsis from 2013 to 2016. Perinatal and clinical characteristics as well as microbiological and laboratory findings were evaluated. Neonatal sepsis was defined as either culture-proven sepsis (positive blood culture) or clinical sepsis (at least one symptom and elevated C-reactive protein (CRP) concentrations within 72 h with negative blood culture). We further differentiated between early-onset (EOS) and late-onset (LOS) sepsis. Results: Microbiological colonization screening by throat and rectal swabs frequently did not detect the organism that subsequently caused the sepsis. Depending on the age of the newborn with sepsis (EOS or LOS), associations between different anamnestic and clinical factors (prenatal or postnatal ones) were found. In particular, the central−peripheral temperature difference showed a strong association with LOS. Laboratory results useful for the early detection of neonatal sepsis included interleukin-6 (IL-6) and CRP concentrations. Conclusions: Elevated IL-6 >100 ng/L was a strong marker for neonatal sepsis. When choosing the antibiotics for treatment, data from microbiological colonization screening should be considered but not solely relied on. Some indicators of infection also depended on postnatal age.

Comparison of the certified Copan eSwab system with commercially available cotton swabs for the detection of multidrug-resistant bacteria in rectal swabs.

BACKGROUND: Rectal swabs are well-implemented screening tools for multidrug-resistant bacteria (MDRB). Since certified swabs such as the Copan eSwab system experienced a delivery bottleneck during the COVID-19 pandemic, commercially available alternatives such as commonly used double-tipped cotton swabs had to be investigated, especially considering their similarity to professional cotton swabs for microbiological purposes. METHODS: Diagnostic properties of commercial cotton swabs (comparable to Q-tips) and Copan eSwabs were qualitatively compared in a prospective single-center study using microbiological standard cultures and PCR methods for the detection of multidrug-resistant Gram-negative bacteria and vancomycin-resistant enterococci (VRE). RESULTS: A total of 196 swab pairs were collected from 164 participants. MDRB were detected in 36 of 164 cases (22%). There were neither false-negative nor false-positive results using commercial cotton swabs. In 8 of 196 samples (4.1%) MDRB species were detected only by using cotton swabs, including vancomycin-resistant Enterococcus faecium, OXA-48 producing Escherichia coli, ESBL-producing Klebsiella pneumoniae and ESBL-producing Escherichia coli. DISCUSSION: Commercial cotton swabs turned out to be a reliable alternative to Copan eSwabs. For practical use as a screening tool, relevant storage- and manufacturer-related contamination must be ruled out beforehand. CONCLUSIONS: Commonly available double-tipped cotton swabs can be used for rectal MDRB screening in the event of supply shortages of certified swabs. Further studies should clarify their suitability as a sampling system for nasopharyngeal MRSA carriage or even for the molecular biological detection of SARS-CoV-2.

Evaluation of a Luminometric Cell Counting System in Context of Antimicrobial Photodynamic Inactivation.

Antimicrobial resistance belongs to the most demanding medical challenges, and antimicrobial photodynamic inactivation (aPDI) is considered a promising alternative to classical antibiotics. However, the pharmacologic characterization of novel compounds suitable for aPDI is a tedious and time-consuming task that usually requires preparation of bacterial cultures and counting of bacterial colonies. In this study, we established and utilized a luminescence-based microbial cell viability assay to analyze the aPDI effects of two porphyrin-based photosensitizers (TMPyP and THPTS) on several bacterial strains with antimicrobial resistance. We demonstrate that after adaptation of the protocol and initial calibration to every specific bacterial strain and photosensitizer, the luminometric method can be used to reliably quantify aPDI effects in most of the analyzed bacterial strains. The interference of photosensitizers with the luminometric readout and the bioluminescence of some bacterial strains were identified as possible confounders. Using this method, we could confirm the susceptibility of several bacterial strains to photodynamic treatment, including extensively drug-resistant pathogens (XDR). In contrast to the conventional culture-based determination of bacterial density, the luminometric assay allowed for a much more time-effective analysis of various treatment conditions. We recommend this luminometric method for high-throughput tasks requiring measurements of bacterial viability in the context of photodynamic treatment approaches.

Pathogens and Shift of Resistance in Early Infections after Operative Fracture Fixation.

Background: Surgical site infections (SSIs) remain a challenge for the healthcare system. During the last 30 years, the literature has shown an increase of gram-negative bacterial strains in multiple infectious sites and that cephalosporins have replaced penicillin as the gold standard in peri-operative antibiotic prophylaxis. This study aims to examine the recent bacterial spectrum in orthopedic early SSIs and to compare it with a historical cohort. Patients and Methods: Patients in a level 1 trauma center with an SSI within six weeks after open fixation of a fracture were analyzed in two adjacent periods from 2007 to 2012 (data pool 1; DP1) and 2013 to 2017 (data pool 2; DP2), retrospectively. The detected microbiologic pathogens and the associated resistograms from both time periods were compared. Results: Six hundred eighty-one smear tests and respective pathogens from the wounds of 463 patients (mean age, 62.6 ± 20 years) with SSIs were analyzed. The following pathogens were found most frequent: Staphylococcus epidermidis (DP1, 20.6%; DP2, 26.3%), Staphylococcus aureus (DP1, 27.1%; DP2, 16.5%), Enterococcus faecalis (DP1, 13.7%; DP2, 11.1%), Bacillus sp. (DP1, 3.0%; DP2, 5.3%), Escherichia coli (DP1, 5.1%; DP2, 4.1%), Pseudomonas aeruginosa (DP1, 3.7%; DP2, 2.5%). In DP2, there were lower primary early infection rates with Staphylococcus aureus than in DP1 (p = 0.002). In DP2, Staphylococcus epidermidis showed an oxacillin resistance in 90.6% and an increased resistance (79.8%; p = 0.069) to several classes of antibiotic agents compared to DP1. Conclusions: No bacterial shift toward gram-negative species was observed in this investigation. However, Staphylococcus epidermidis showed an increased antibiotic resistance in the more recent patient cohort. The incidence of SSIs with Staphylococcus aureus decreased substantially.

The Meta-Substituted Isomer of TMPyP Enables More Effective Photodynamic Bacterial Inactivation than Para-TMPyP In Vitro.

Porphyrinoid-based photodynamic inactivation (PDI) provides a promising approach to treating multidrug-resistant infections. However, available agents for PDI still have optimization potential with regard to effectiveness, toxicology, chemical stability, and solubility. The currently available photosensitizer TMPyP is provided with a para substitution pattern (para-TMPyP) of the pyridinium groups and has been demonstrated to be effective for PDI of multidrug-resistant bacteria. To further improve its properties, we synthetized a structural variant of TMPyP with an isomeric substitution pattern in a meta configuration (meta-TMPyP), confirmed the correct structure by crystallographic analysis and performed a characterization with NMR-, UV/Vis-, and IR spectroscopy, photostability, and singlet oxygen generation assay. Meta-TMPyP had a hypochromic shift in absorbance (4 nm) with a 55% higher extinction coefficient and slightly improved photostability (+6.9%) compared to para-TMPyP. Despite these superior molecular properties, singlet oxygen generation was increased by only 5.4%. In contrast, PDI, based on meta-TMPyP, reduced the density of extended spectrum ß-lactamase-producing and fluoroquinolone-resistant Escherichia coli by several orders of magnitude, whereby a sterilizing effect was observed after 48 min of illumination, while para-TMPyP was less effective (p < 0.01). These findings demonstrate that structural modification with meta substitution increases antibacterial properties of TMPyP in PDI.

Surgical Revision Promotes Presence of Enterococcus spp. in Abdominal Superficial Surgical Site Infections.

BACKGROUND: Superficial surgical site infections (SSSIs) are a major reason for morbidity after abdominal surgery. Microbiologic isolates of SSSIs vary widely geographically. Therefore, knowledge about the specific bacterial profile is of paramount importance to prevent SSSI. METHODS: We performed a subgroup analysis of the microbiological isolates from patients with SSSI after abdominal surgery that were included in our institutional wound register. We aimed at identifying predominant strains as well as risk factors that would predispose for SSSI with certain bacteria. RESULTS: A total of 494 patients were eligible for analysis. Of those 313 had received wound swaps, with 268 patients yielding a bacterial isolate. Enterobacterales (31.7%) and Enterococcus spp. (29.5%) were found as main bacteria in SSSI, with 62.3% of the wounds being polymicrobial. As risk factors for changes in bacterial isolates, we identified operative revision (OR 3.032; 95%CI 1.734-5.303) in multivariate analysis. Enterococcus spp. showed a significant increase in patients after revision surgery (p<0.001). Antibiotic therapy was neither influential on bacterial changes nor on the presence of Enterococcus spp. in SSSI. CONCLUSION: Our study accentuates the high frequency of Enterococcus spp. in SSSI after abdominal surgery, while identifying surgical revision as major risk factor. The results urge vigilance in the treatment of patients with surgical revisions to include Enterococcus spp. in the prevention and treatment strategies.

Antibiotic Resistance Patterns of Bacterial Isolates from Neonatal Sepsis Patients at University Hospital of Leipzig, Germany.

Neonatal sepsis caused by resistant bacteria is a worldwide concern due to the associated high mortality and increased hospitals costs. Bacterial pathogens causing neonatal sepsis and their antibiotic resistance patterns vary among hospital settings and at different points in time. This study aimed to determine the antibiotic resistance patterns of pathogens causing neonatal sepsis and to assess trends in antibiotic resistance. The study was conducted among neonates with culture proven sepsis at the University Hospital of Leipzig between November 2012 and September 2020. Blood culture was performed by BacT/ALERT 3D system. Antimicrobial susceptibility testing was done with broth microdilution method based on ISO 20776-1 guideline. Data were analyzed by SPSS version 20 software. From 134 isolates, 99 (74%) were gram positive bacteria. The most common gram positive and gram negative bacteria were S. epidermidis, 51 (38%) and E. coli, 23 (17%), respectively. S. epidermidis showed the highest resistance to penicillin G and roxithromycin (90% each) followed by cefotaxime, cefuroxime, imipenem, oxacillin, and piperacillin-tazobactam (88% each), ampicillin-sulbactam (87%), meropenem (86%), and gentamicin (59%). Moreover, S. epidermidis showed raising levels of resistance to amikacin, gentamicin, ciprofloxacin, levofloxacin, moxifloxacin, and cotrimoxazol. Gram positive bacteria showed less or no resistance to daptomycin, linezolid, teicoplanin, and vancomycin. E. coli showed the highest resistance to ampicillin (74%) followed by ampicillin-sulbactam (52%) and piperacillin (48%). Furthermore, increasing levels in resistance to ampicillin, ampicillin-sulbactam, piperacillin, and cefuroxime were observed over the years. Encouragingly, E. coli showed significantly declining trends of resistance to ciprofloxacin and levofloxacin, and no resistance to amikacin, colistin, fosfomycin, gentamicin, imipenem, piperacillin-tazobactam, and tobramycin. In conclusion, this study demonstrates that gram positive bacteria were the leading causes of neonatal sepsis. Bacterial isolates were highly resistant to first and second-line empiric antibiotics used in this hospital. The high levels of antibiotic resistance patterns highlight the need for modifying empiric treatment regimens considering the most effective antibiotics. Periodic surveillance in hospital settings to monitor changes in pathogens, and antibiotic resistance patterns is crucial in order to implement optimal prevention and treatment strategies.

Changes in antibiotic consumption, AMR and Clostridioides difficile infections in a large tertiary-care center following the implementation of institution-specific guidelines for antimicrobial therapy: A nine-year interrupted time series study.

BACKGROUND: Institution-specific guidelines (ISGs) within the framework of antimicrobial stewardship programs offer locally tailored decision support taking into account local pathogen and resistance epidemiology as well as national and international guidelines. OBJECTIVES: To assess the impact of ISGs for antimicrobial therapy on antibiotic consumption and subsequent changes in resistance rates and Clostridioides difficile infections (CDIs). METHODS: The study was conducted at the Leipzig University Hospital, a 1,451-bed tertiary-care medical center, and covered the years 2012 to 2020. Since 2014, ISGs were provided to optimize empirical therapies, appropriate diagnostics, and antimicrobial prophylaxis. We used interrupted time series analysis (ITSA) and simple linear regression to analyze changes in antimicrobial consumption, resistance and CDIs. RESULTS: Over the study period, 1,672,200 defined daily doses (DDD) of antibiotics were dispensed, and 85,645 bacterial isolates as well as 2,576 positive C. difficile cultures were collected. Total antimicrobial consumption decreased by 14% from 2012 to 2020, without clear impact of the deployment of ISGs. However, implementation of ISGs was associated with significant decreases in the use of substances that were rarely recommended (e.g., fluoroquinolones). Over the whole study period, we observed declining resistance rates to most antibiotic classes of up to 25% in Enterobacterales, staphylococci, and Pseudomonas aeruginosa. Switching from ceftriaxone to cefotaxime was associated with reduced resistance to third-generation cephalosporins. The number of CDI cases fell by 65%, from 501 in 2012 to 174 in 2020. CONCLUSIONS: Well-implemented ISGs can have a significant, immediate, and lasting impact on the prescription behavior. ISGs might thereby contribute to reduce resistance rates and CDI incidences in the hospital setting.

Hypervirulent Klebsiella pneumoniae of Lineage ST66-K2 Caused Tonsillopharyngitis in a German Patient.

Hypervirulent Klebsiella pneumoniae (hvKp) is a novel pathotype that has been rarely described in Europe. This study characterizes a hvKp isolate that caused a community-acquired infection. The hypermucoviscous Klebsiella pneumoniae (K. pneumoniae) strain 18-0005 was obtained from a German patient with tonsillopharyngitis in 2017. Antibiotic susceptibility testing was performed and the genome was sequenced by Illumina and Nanopore technology. Whole genome data were analyzed by conducting core genome multilocus sequence typing (cgMLST) and single nucleotide polymorphism (SNP) analysis. Virulence genes were predicted by applying Kleborate. Phenotypic and whole genome analyses revealed a high similarity of the study isolate 18-0005 to the recently reported antibiotic-susceptible hvKp isolate SB5881 from France and the "ancestral" strain Kp52.145; both were assigned to the ST66-K2 lineage. Comparative genomic analysis of the three plasmids showed that the 18-0005 plasmid II differs from SB5881 plasmid II by an additional 3 kb integrated fragment of plasmid I. Our findings demonstrate the genetic flexibility of hvKp and the occurrence of a strain of the clonal group CG66-K2 in Germany. Hence, it emphasizes the need to improve clinical awareness and infection monitoring of hvKp.

Photosensitizer-loaded hydrogels for photodynamic inactivation of multirestistant bacteria in wounds.

Photodynamic treatment is a promising tool for the therapy of multidrug-resistant bacteria. In this study, we highlight photosensitizer-loaded hydrogels as an application system for infected wounds. The poly(ethylene glycol) diacrylate-based and electron beam-polymerized hydrogels were mechanically stable and transparent. They were loaded with two photoactive, porphyrin-based drugs - tetrakis(1 methylpyridinium-4-yl)porphyrin p-toluenesulfonate (TMPyP) and tetrahydroporphyrin - p toluenesulfonate (THPTS). The hydrogels released a sufficient amount of the photosensitizers (up to 300 µmol l-1), relevant for efficiency. The antimicrobial effectivity of loaded hydrogels was investigated in a tissue-like system as well as in a liquid system against a multiresistant Escherichia coli. In both systems, light induced eradication was possible. In contrast, hydrogels alone showed only minor antimicrobial activity. Furthermore, the loaded hydrogels were successfully tested against seven multidrug-resistant bacterial strains, namely Enterococcus faecium, Staphylococcus aureus, Klebsiella pneumonia, Acinetobacter baumannii, Pseudomonas aeruginosa, Escherichia coli and Achromobacter xylosoxidans. The eradication of these pathogens, except A. xylosoxidans, was successfully demonstrated. In general, TMPyP-loaded hydrogels were more effective than THPTS-loaded ones. Nevertheless, both photosensitizers displayed effectivity against all investigated bacteria strains. Taken together, our data demonstrate that photosensitizer-loaded hydrogels are a promising new tool to improve the treatment of wounds infected with problematic bacterial pathogens.